Caverns - Area 1: Excavation Transfer

Caverns - Area 1: Excavation Transfer is the twenty-fifth level of Doom 3. The player advances towards the primary excavation site, where the Hell portal is located. Level 1 contains the oldest, original Mars base. It is also the last level to feature both the non-player characters, and their PDAs, as well as former human enemies.

Summary
Starting off from where Site 3 ended, the elevator takes the marine into Caverns Area 1 - the location of the very first human base established on Mars. He arrives at the Base 1 Materials Transfer point. From there, he heads to the Heavy Lift Transfer while battling hordes of demons, including trites, imps, wraiths, commandos, cacodemons, an arch-vile, and a Hell knight. After unlocking the Heavy Lift controls, he rides the massive lift down to Sub Chamber 2. Throughout all this, the caverns are constantly plagued with tremors and quakes.

Upon reaching Sub Chamber 2, the marine fights his way to Environmental Monitoring, where he finds he needs a keycard to go further. To find the card, he must take a detour to the Thermal Regulation Pump. There are no enemies here, but the marine has to instead navigate his way down a hazardous maintenance shaft which consists of four platforms that continuously extend and retract themselves. He manages to safely make his way to the bottom of the shaft where he discovers a lone survivor hiding behind some pipes. The survivor, J. Katayama, gives him the access card he needs. The marine then heads back up the shaft and returns to Environmental Monitoring (battling a swarm of cacodemons waiting for him outside).

Using Katayama's access card, the marine enters the conference room (where he finds Bob Cody's PDA), and from there, he fights his way to Base 2 Materials Transfer Lift. A lava filled chasm separates this area from his next destination, so he must activate a crane and walk across it to the other side. He then goes to the Personnel Transfer Station and kills the horde of demons that try to ambush him there. He activates an elevator, kills the Hell knight that emerges from it, and rides the elevator down to Materials Handling. He then fights his way to Sub Station 3 Transfer, which will take him to Caverns Area 2.

Areas

 * Base 1 Materials Transfer
 * Base 1 Junction 1
 * Base 1 Junction 2
 * Containment Monitoring
 * Base 1 Junction 3
 * Heavy Transfer Lift 1
 * Heavy Lift Control
 * Storage 2D
 * Living Quarters 1A
 * Main Transfer Lift Shaft
 * Sub Chamber 2
 * Environmental Monitoring
 * Thermal Regulation Pump
 * B1 Conference Room 1
 * B1 Sub Junction
 * B2 Material Transfer Lift
 * B1 Junction 2
 * Personell Transfer Station
 * Transfer Shaft 2A
 * Materials Handling
 * Sub Station 3 Transfer Point

Objectives

 * Access lower levels
 * Activate the Service Lift to reach the lower levels of the Caverns.


 * Security Access.
 * Locate the Security Card to gain access to the dig site.

Routes and tricks
It is possible to use a rocket jump in Sub Chamber 2 to reach the higher set of catwalks from the lower set of them, skipping the interior of the building (Environmental Monitoring) entirely.

The large pit at B2 Material Transfer Lift can, despite its dizzying height, actually be descended without taking a fatal amount of fall damage, by hugging the rightmost wall in a certain manner which is difficult to describe. When executed properly, this skips a large section of the level including the large battle at Personnel Transfer Station and the arch-vile encounter in Material Handling.

Characters

 * J. Katayama
 * Malcolm Betruger (voice only)

PDAs

 * Robert Cody. Found in B1 Conference Room 1.

Enemies
The enemy count on Nightmare is the same as on Veteran.

1. Some imps, wraiths, cacodemons and Hell knights are spawned by arch-viles, thus their amount may vary. Here only the number of distinct spawn points is shown.

2. Two Hell knights have lower health than standard, 500 and 600 instead of the normal 900.

Items
The item count on Nightmare is the same as on Veteran, except the med kits are absent. The only change in the amount of items in BFG Edition is the addition of a single adrenaline powerup to the level. There are three health stations on the level, one with 82 health and the other two with 32 health in reserve (all of them have 100 health in BFG Edition).

Starting inventory
If the player starts the level via a console command, they will start with these items:

Secrets

 * In the very first room there's a hole in a floor with armor and grenades in there.
 * In Base 1 Junction 1 there's a small shell box hidden in a pile of rocks.
 * In Heavy Transfer Lift 1 there a gap between the lift and the platform with the ladder leading inside it. There's small passage inside this gap with a chain gun, ammo, and armor.
 * In Environmental Monitoring there are a couple of clips hidden on top of some machinery boxes in the center of the room.
 * In Sub Chamber 2, when the player has to climb the ladder to the top of the building (to get the access card), the player can jump off said ladder to access the roof of the lower level of the building and find a plasma gun with ammo there.
 * When the player exits B1 Conference Room 1, there's a ladder on the left hidden in a dark area. Upon climbing this ladder a wraith will attack the player and a door to a maintenance hatch will open, revealing a cache of ammo.
 * After the player uses the crane to get to the other side of B2 Material Transfer Lift, some items will be hidden inside large metal pipes in the area.
 * In Personnel Transfer Station there are a few items hidden behind the crates; besides, one of the crates is open on the top and can be jumped into and will contain some ammo.
 * In Materials Handling there are some supplies hidden behind explosive barrels and more supplies hidden behind crates in the area.

Trivia

 * On the original Xbox version of the game this level was divided into two parts: Caverns - Area 1 and Caverns - Area 1 Sublevel.
 * Robert Cody refers in his PDA to the earthquakes (or "Mars-quakes") which plague this area as "howlers," because they are accompanied by a mysterious screaming. The player can hear one such howler near the beginning of Caverns - Area 2: Artifact Excavation.